The invention relates to a device for supplying fuel for a rocket propulsion unit, particularly for a rocket propulsion unit which is based on the combustion of hydrogen and oxygen in the expander circuit, as well as to a heat exchanger to be used in said device for supplying fuel.
For the injection of hydrogen and oxygen into the propulsion chamber of a rocket, the fuel situated in the tanks, for example, hydrogen and oxygen, must be fed at high pressure in a controlled manner. In this case, the hydrogen is first guided by way of control valves into the area outside the propulsion chamber so that, on the one hand, the hydrogen causes a cooling of the combustion chamber wall and, on the other hand, in the case of the expander circuit, because of the heat generated by the combustion events in the combustion chamber, the hydrogen itself is heated for the later expansion in turbines. At a corresponding temperature of the hydrogen, the latter can drive turbines which, in turn, cause the driving of pumps for feeding hydrogen and oxygen to the injection elements at a sufficient pressure. In order to reach a combustion chamber pressure in the rocket propulsion unit which is as high as possible, it is required that devices of this type have a more efficient method of operation.
From the state of the art reflected in U.S. Pat. Nos. 3,049,870; 5,410,874; and 4,583,362 it is known to provide a heat exchanger with a rocket propulsion system, in which the fuel from a turbine exchanges heat with fuel from a pump in order to achieve a further heating of the fuel. However it is problematical with this state of the art in that, in spite of the additional heating, under the circumstances there the desired combustion chamber pressure is not achieved and furthermore the arrangement requires a relatively large space.
It is therefore an object of the invention to provide an optimum arrangement for supplying fuel for a rocket propulsion unit with an expander circuit which, as a whole, operates more efficiently and increases the combustion chamber pressure for rocket propulsion units.
This object is achieved by a device for supplying fuel for a rocket propulsion unit having a first and at least a second fuel circuit, each fuel being brought to an increased energy level by means of a pump and being supplied for combustion by way of injection elements, the first fuel being heated in cooling channels extending in a propulsion chamber wall before the fuel is supplied for combustion, and the first fuel subsequently being fed to at least the turbines assigned to the pumps, characterized in that a heat exchanger is provided in which the fuel coming from the turbines is in a heat exchange with a fuel coming from a pump. Alternative embodiments are described in the claims.
In the following, the invention will be described by means of the attached FIGS. 1 to 3.